You do not want to remove then from mom before they are at least 3 weeks, at 2 weeks they will run around however they are only starting to eat solid food and still needs to be with their mother, at 3 weeks they can safely be weaned, 4 weeks if they are runts, by that time they are fine on their own and no longer need their mother, they will eat and drink on their own.
My guess you might remove them a bit early.
Rats are designed to produce large litters if that worries you try to do communal nursing.
I usually have them in individual birthing tubs for the first week to cut down on fighting and loss and after that I have 2 to 3 females per tubs in my communal nursing tubs, then by week 3 babies are seperated and the females go back in rotation.
Hope that helps.
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